The "unpublished" command:

Usage: fossil unpublished ?OPTIONS?
Show a list of unpublished or "private" artifacts. Unpublished artifacts
will never push and hence will not be shared with collaborators.
By default, this command only shows unpublished check-ins. To show
all unpublished artifacts, use the --all command-line option.
OPTIONS:
--all Show all artifacts, not just check-ins